In the rproc_alloc() function, on error, put_device(&rproc->dev) is
called, leading to the call of the rproc_type_release() function.
An error can occurs before ida_alloc is called.
In such case in rproc_type_release(), the condition (rproc->index >= 0) is
true as rproc->index has been initialized to 0.
ida_free() is called reporting a warning:
[ 4.181906] WARNING: CPU: 1 PID: 24 at lib/idr.c:525 ida_free+0x100/0x164
[ 4.186378] stm32-display-dsi 5a000000.dsi: Fixed dependency cycle(s) with /soc/dsi@5a000000/panel@0
[ 4.188854] ida_free called for id=0 which is not allocated.
[ 4.198256] mipi-dsi 5a000000.dsi.0: Fixed dependency cycle(s) with /soc/dsi@5a000000
[ 4.203556] Modules linked in: panel_orisetech_otm8009a dw_mipi_dsi_stm(+) gpu_sched dw_mipi_dsi stm32_rproc stm32_crc32 stm32_ipcc(+) optee(+)
[ 4.224307] CPU: 1 UID: 0 PID: 24 Comm: kworker/u10:0 Not tainted 6.12.0 #442
[ 4.231481] Hardware name: STM32 (Device Tree Support)
[ 4.236627] Workqueue: events_unbound deferred_probe_work_func
[ 4.242504] Call trace:
[ 4.242522] unwind_backtrace from show_stack+0x10/0x14
[ 4.250218] show_stack from dump_stack_lvl+0x50/0x64
[ 4.255274] dump_stack_lvl from __warn+0x80/0x12c
[ 4.260134] __warn from warn_slowpath_fmt+0x114/0x188
[ 4.265199] warn_slowpath_fmt from ida_free+0x100/0x164
[ 4.270565] ida_free from rproc_type_release+0x38/0x60
[ 4.275832] rproc_type_release from device_release+0x30/0xa0
[ 4.281601] device_release from kobject_put+0xc4/0x294
[ 4.286762] kobject_put from rproc_alloc.part.0+0x208/0x28c
[ 4.292430] rproc_alloc.part.0 from devm_rproc_alloc+0x80/0xc4
[ 4.298393] devm_rproc_alloc from stm32_rproc_probe+0xd0/0x844 [stm32_rproc]
[ 4.305575] stm32_rproc_probe [stm32_rproc] from platform_probe+0x5c/0xbc
Calling ida_alloc earlier in rproc_alloc ensures that the rproc->index is
properly set.
Fixes: 08333b911f01 ("remoteproc: Directly use ida_alloc()/free()")
Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxxxxxxx>
---
Note for backporting to previous kernel versions: The SHA 08333b911f01
seems to correspond to the last commit that updated IDA allocation.
The issue existed before, but the fix could not be applied without some
rework.
---
drivers/remoteproc/remoteproc_core.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index f276956f2c5c..ef6febe35633 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -2486,6 +2486,13 @@ struct rproc *rproc_alloc(struct device *dev, const char *name,
rproc->dev.driver_data = rproc;
idr_init(&rproc->notifyids);
+ /* Assign a unique device index and name */
+ rproc->index = ida_alloc(&rproc_dev_index, GFP_KERNEL);
+ if (rproc->index < 0) {
+ dev_err(dev, "ida_alloc failed: %d\n", rproc->index);
+ goto put_device;
+ }
+
rproc->name = kstrdup_const(name, GFP_KERNEL);
if (!rproc->name)
goto put_device;
@@ -2496,13 +2503,6 @@ struct rproc *rproc_alloc(struct device *dev, const char *name,
if (rproc_alloc_ops(rproc, ops))
goto put_device;
- /* Assign a unique device index and name */
- rproc->index = ida_alloc(&rproc_dev_index, GFP_KERNEL);
- if (rproc->index < 0) {
- dev_err(dev, "ida_alloc failed: %d\n", rproc->index);
- goto put_device;
- }
-
dev_set_name(&rproc->dev, "remoteproc%d", rproc->index);
atomic_set(&rproc->power, 0);
base-commit: adc218676eef25575469234709c2d87185ca223a
--
2.25.1
